An N-carbamoyl-tert-leucine, which can be produced by carbamoylizing the amino group of tert-leucine, i.e. 2-amino-3,3-dimethyl butanoic acid, is useful as a synthesis intermediate for various pharmaceutical products and agrochemicals. In particular, it is reported in Patent Document 1 that N-tert-butylcarbamoyl-L-tert-leucine is very useful as a precursor of a hepatitis C virus protease inhibitor.
In general, it has been well-known as a method for synthesizing an N-carbamoyl-amino acid that an amino acid is mixed with an isocyanic acid compound for reaction (Non-patent Document 1 and Patent Document 2).
Non-patent Document 1: “Jikken Kagaku Koza (The course of chemical experiment) 5th edition”, MARUZEN Co. Ltd., vol. 14, p. 429
Patent Document 1: JP 2006-528133 T
Patent Document 2: JP 60-155968 A